Anycast is a feature of IPv4 and IPv6 networks that allows you to assign the same IP address to multiple devices. When attempting to reach a device with such an address, the employed routing protocols will route to the closest device using that address. "Closest" typically means the lowest cost or metric based on the routing protocol used.

This is useful for applications that employ globally distributed systems, allowing the same address to be used on multiple continents, thus geographically distributing traffic to such systems. This is beneficial especially to employ load distribution between multiple geographically dispersed servers, as well as reducing latency by ensuring communication with the "closest" server (least cost).

Anycast does not use particular address ranges, nor does it require a specific configuration. You simply assign the same address to multiple devices. However, you must make sure that the routing protocols being used correctly route such traffic. Otherwise unpredictable routing may result.

Anycast is also useful for employing Multicast Anycast RP when deploying multicast networks.